1. Field
This invention relates to dental control units. It is particularly directed to easily cleaned and sterilized dental control units of the "Continental" type, having pivoting arm supports for conduits connected to dental handpieces.
2. State of the Art
Dental control units provide for chairside positioning of dental handpiece-supporting trays. They usually include control structure for the handpieces. The control units are supported for pivotal movement on a cantilevered swinging arm so that they may be positioned closely adjacent the oral cavity of a dental patient. They are intended to be easily accessible to a dentist or dental technician, without obstructing the view or necessary operating room of the dentist and without being obtrusive to a patient.
Dental control units in general include a base mounted to swing with and to pivot on a support arm. A housing fits over the base to provide a cover for control mechanisms carried by the base and serving as flow control means for utility supply conduits extending from the base. Typical such dental control units support a plurality of dental handpieces, the associated utility supply conduits and structure for controlling flow through the conduits.
U.S. Pat. No. 4,173,827, for example, discloses a module control block assembly to individually control drive air and air and water coolants to conduits to which dental handpieces are connected.
U.S. Pat. No. 4,230,452 discloses a multiple dental handpiece control system in which lifting one handpiece out of its hangar blocks supply of power and coolants to all other handpieces. Each handpiece has an individual control unit and a blockout unit. When a handpiece is lifted from its hangar, it activates a valve to cause a piston in its control unit to shift to an operating condition. Power and coolant fluid are thus supplied to that handpiece. Power to the pistons in the other control units is simultaneously blocked, thereby preventing flow of power and coolant fluids to the other handpieces.
In "Continental" style dental control units, the supply conduits extend through semi-rigid, pivoted support arms. These arms are provided to maintain separation of the conduits, to prevent tangling of the conduits and other structure and to ensure proper positioning of the handpieces on the top surface of the housing when not in use. The conduits terminate in quick release ends to which dental handpieces are attached, and provide means for supplying vacuum, water, air and various solutions to the handpieces. Each handpiece has an individual control unit and a blockout unit. When a handpiece is lifted from its hangar, it activates a valve to cause a piston in its control unit to shift to an operating condition. Power and coolant fluid are thus supplied to that handpiece. Power to the pistons in the other control units is simultaneously blocked, thereby preventing flow of power and coolant fluids to the other handpieces.
In general, the support arms of previously known "Continental" type control units have been pivotally connected to an upper rear surface of a base of a dental control unit. As so connected, they swing from the pivot connection forwardly and rearwardly with respect to the unit between a use and rest position, respectively. These support arms are conventionally referred to as "whips" or "whip arms." A conduit is passed through each whip arm. A proximal end of the conduit is connected to a flow control valve mounted on the base, inside the housing. A distal free end of the conduit carries a connector to which a dental handpiece may be attached. An intermediate portion of each conduit is passed through a whip arm. When the dental handpiece is grasped, lifted off a hangar, or top tray surface, of the housing and moved towards a patient in a dental chair, the whip arm rotates about its pivot connection and forwardly towards and over the dental control unit housing.
Dental control units having whip arms to support the conduits attached to dental handpieces have been widely accepted. However, the whip arms heretofore used have been connected at, or adjacent to, the top surface of a dental unit so that the entire pivot connection assembly is exposed to oral cavity spray. The pivot connection, if exposed to the spray, must be disinfected between use of the assembly with different patients. Currently, barrier protection is relied upon to eliminate the need for disinfection after each patient treatment, but this expedient is generally unsatisfactory. An improperly positioned barrier is ineffective. A properly positioned barrier, from the standpoint of effectiveness, tends to obstruct proper pivoting of the arms.
The conduits of currently conventional Continental units exit the housing of the dental unit before entering the whip arms. Accordingly, portions of these conduits are exposed to spray contamination. Conduits which are contaminated in this fashion are difficult to clean in compliance with modern asepsis requirements.